Recently I was chatting at a wine tasting event with a couple of lawyers, who I had just met. One was surprisingly inquisitive about my work in the software requirements arena. Apparently she was working on case involving software at that very time. At one point she asked me, “How do you know how detailed to make the requirements?” It’s an insightful question, one that even experienced business analysts often ask me.

There’s no single correct answer to this question, even assuming we could agree on exactly how to measure requirements “detail.” This is one of those thorny issues that plague BAs. For most such issues, the correct answer is, “It depends.” Despite being true, that’s not a very satisfying reply. Even though there is no simple answer to this simple question, I can give you some ways to think about how much detail is appropriate in a given situation. This is the first in a series of three articles adapted from my book More about Software Requirements (Microsoft Press, 2006).